Curse of the Crimson Crown

CotCT in a Pathfinder Weird West Setting

the Silt Sea

Made up of fine particulate, out as far as anyone remembers. The first colonists that came from far out west came at great cost, and many people were lost to monsters beyond the scope of what people thought were possible – it became abundantly clear that another trip would not be survived by anyone. And so when they arrived, they established themselves as though there were no other options.
With great skill and special gear, one can walk on the silt for a time, though the creatures that swim in the Silt are fierce, and most people prefer to stay as close to the “shore” as they can (and remain within reinforced Siltships). Some of the creatures make for good eating, however, and so there will always be those who fish to feed their families.